I want to shoot with the sun behind my subject but maybe spilling a bit around the head. I want to maintain the details in the sky, blue and puffy white clouds but have the subject properly exposed. I want to shoot from a low perspective. So....I want to expose for the sky and use fill flash for my subject, right? Should I use the flash on camera or off? Do Whick setting would be the best for the flash? Any help would be appreciated. Thanks.